Genetic Therapy Inc. (GTI) announced Friday that the RAC has approved its gene therapyprotocol for treating a form of metastatic cancer known as leptomeningeal carcinomatosis.

In this type of cancer, tumor cells seed the coverings of the brain and spinal cord(leptomeninges); mean survival time is six to seven months.

Edward Oldfield and Zvi Ram of the National Institute of Neurological Disorders andStroke will serve as the trial's principal investigators (Pls).

The treatment approach used in this protocol, which still has to be approved by theFDA, employs GTI's vector systems to transfer the gene for the enzyme thymidine kinaseinto dividing tumor cells. Cells producing the enzyme become susceptible to the anti-viraldrug ganciclovir, which can then be administered to destroy the tumor cells.

GTI of Gaithersburg, Md., is using a similar approach in its ongoing gene therapy trialin brain tumors (in which Oldfield and Ram are the Pls, as well). In September, thecompany reported the preliminary results of the brain tumor trial at the 10thInternational Conference on Brain Tumor Research and Therapy in Stalheim, Norway. In thattrial, five of the eight treated patients had exhibited an anti-tumor response and all ofthem tolerated the treatment well.

-- Jennifer Van Brunt